Navigation signal system



E. PENTON NAVIGATION SIGNAL SYSTEM Jan. 4, 1949.

2 Sheet-Sheet 1 Filed May 19, 1944 E W H W A TTORNE) Jan. 4, 1949. WPENTON 2,458,414

NAVIGfVIION SIGNAL SYSTEM Filed May 19, 1944 2 sheets-sheet 2 M/A E/VMAEDGAR 1M Pf/VTO/V @144, find,

ATTORNEY Patented Jan. 4, 1949 NAVIGATION SIGNAL SYSTEM Edgar W. Penton,Fairfax County, Va.

Application May 19, 1944, Serial No. 536,397

Claims.

This present invention relates to a system of signalling and moreparticularly to direction control lights for indicating to a navigatorany predetermined course.

In control lights heretofore in use, such for example as range lightsfor directing a vessel on a proper course, it has been the practice toprovide two lights in alinement and coincident with the course orchannel which the vessel is to follow, so that when the navigator hasthese two lights in line he knows the vessel is in the proper channel oron the course. With two such lights necessity requires the finding oftwo sites for lamp installation at the proper points for true bearingwith the incident expense of erection. Furthermore, the lights andstructures have to be maintained in operation with the attendant laborand service costs.

Some of the objects of the present invention are: to provide an improvedlight system for marine or aerial navigation; to provide a light systemwherein control is established by using a single unit for establishmentof the true course; to provide a light system wherein lights at twospaced sites are unnecessary; to provide a light system wherein aplurality of different colored lights operate from a common site fordirection indication; to provide a novel system of direction controllights wherein a beam of light visibly different from other beamsindicates a true course while the other beams indicate variation fromthe true course; to provide a unidirectional beam of light which whenviewed from a specific angle and within a very narrow range presents onepeculiar appearance, while viewed from other angles it presents adiiferent appearance; to provide a signalling system as a groundinstallation as an aid to navigators for guiding ships or airplanes on atrue course, or as an installation on ships or airplanes for indicatingto observers th course or altitude of the ship or airplane; to provide anovel flashing signal as a means for indicating a true course and anyvariation from such course; to utilize the phenomenon of addition ofmutually complemental colors to establish by overlapping beams asubstantial line of a visual effect contrasted with the visual effectsof either of said colored beams; to indicate a course and deviationsfrom the course; to provide a flashing course signal which gives asuccession of spaced or overlapping substantially white signals whendirectly on a course, which gives a flashing alternation of white andone color or white and another color complemental of the first, whenslightly oiT the course, and which gives a succession of flashes of onecolor or its complement when appreciably off the course; and to provideother improvements as will hereinafter appear.

Applicant has discovered that by taking two sharply defined beams oflight similar to search light beams, which emanate from light sourceslocated close together or in the same housing and which are respectivelycolored with complemental colors such, illustratively, as red and green,for instance, and by bringing these beams to bear at such angles thatthe edge of one beam just slightly overlaps the edge of the other beam,there will be established a combined beam having certain unique andimportant characteristics.

In the accompanying drawings, Fig. 1 is a graph of light beam candlepower with reference to the angle of dispersion; Fig. 2 is a graph ofcandle power of two light beams illustrating the resultant effect ofoverlap of the two beams to establish an axis of symmetry coincidentwith a course to be followed; Fig. 3 is adiagram of two light beamsfunctioning in accordance with one form of the present invention; Fig. 4is a graph representation for visualizing the light intensities of Fig.3 from several planes of observation; Fig. 5 is a diagram of three lightbeams functioning in accordance with the invention; Fig. 6 is a graphrepresentation for visualizing the light intensities of Fig. 5 fromseveral planes of observation; Fig. '7 is a chart illustrative of oneform of timing of the light system of Fig. 5; Fig. 8 is a diagram offour light beams functioning in accordance with the invention; Fig. 9 isa graph representation for visualizing the light intensities of Fig. 8from several planes of observation; Fig. 10 is a, chart illustrative ofone form of timing of the light system of Fig. 8; Fig. 11 representsdiagrammatically a front elevation of a light projecting unit; Fig. 12represents a diagrammatic side elevation of theunit of Fig. 11; Fig. 13is a graph illustrating more clearly the cross section relation of thecombined beams of Fig. 4, the section being taken on line l3l3 of Fig.3; and Fig. 14 is a graph of the illumination curves of the three lightbeams of Fig. 5.

In Figure 1 is shown an illumination curve of a sharply defined beamshowing beam candle power at various degrees of divergence from the axisof the beam.

In Figure 2 is shown the resultant candle power curve if two identicalbeams of this character are trained so that their axes diverge by, avery few degrees. A new common axis is formed mid-way and symmetricallybetween the original axes of the two beams, and with a peak candle powergreater than either beam above. The common axis is a substantial linepartaking of equal amounts of energy from both beams. In the verticalcross section of the combined beams shown in Fig. 13 the line ABrepresents the plane of equal visual values derived from the two beams.

If now one of these beams is of a distinctive color such as red, and theother beam is of another color such as green, the combined beams willhave a different and distinctive appearance when viewed from difierentangles.

When viewed from a point directly along the common axis, the appearancewill be practically white if the colors used are mutually complementalrailway signal red and railway signal green. If viewed from a point veryslightly to the right (in approaching the lights), the color will beimmediately red while a slight deviation to the left will give a greenindication. The reason for this is that although the light seen is stilla combination of the two colors, when the angularity changes to theright the candle power of the red beam increases so rapidly while thecandle power of the green decreases so rapidly, so the red energy is sopreponderant over the green energy that a very slight deviation servesto convince the eye that it sees only red. Similar efiects in the greendominance follow a slight deviation to the left from the symmetricalcommon axis.

If, therefore, the common symmetrical axis is caused to be substantiallycoincident with a desired course, such course can be followed accuratelyeven though several miles may intervene between the observer and thelight sources.

An addition to this ranging system can be made by combining additionalbeams both for the pur pose of delineating intermediate angularities ofdeviation from the course or for distinguishing these lights from othercompeting or background lights.

For instance, if a white beam is added to the assembly and trained withits axis along the common axis of the two colored beams substantiallycoincident with the course as in Fig. 5, and then this white beam isflashed alternately with the two colored beams, the result will be thatwhen the observer is approaching the lights exactly on course as at A, asteady substantially white light or a succession of pulses ofsubstantially white light, depending on the timed rate, will be seen.When the observer is in the area AB, slightly oil of the course A, analternate red and white light or flashes of alternate red and whitelight will be seen, while in the area BB', appreciably off of course A,a flashing red light with dark intervals will be seen by the observer.Similarly, on the green side the observer will see alternate green andwhite light or flashes of light in the area AC, close to course A, withflashes of green spaced by dark intervals in the area C-C', appreciablyoil of course A. Fig. 14 is an illumination curve diagram showingappropriate values of the white beam in relation to the values of thetwo colored beams. From this it will be seen that it is unnecessary toflash the colored beams in order to obtain the desired result because inthe area AB the red cannot be seen when the white is on due to thehigher intensity of the white, and in the area B-B' the white cannot beseen, even when on, because of the higher intensity of the red. The samecondition exists for the respective areas AC and -0 when considering thewhite and green beams.

If four beams are used in the ranging unit, as shown in Fig. 8, theymight be comprised of two whites instead of the one white in Fig 5 inaddition to the basic double beam of contrasting colors. In this case avariety of timing arrangements are possible. For instance, if the twocolors are on together, then one white only of the two, then the twocolors on together again, followed by the other of the two white only,and repeat, and with the white beams trained so as to overlap and bedirected along the course, the result will be as follows: On the courseat A the observer will see a continuous substantially white orsuccession of whites. In the area AB he will see red-whitereddark, andrepeat. In the area AC he will see greenwhitegreen-dark, and repeat. Inthe area BB' he will see red flashes with dark intervals and similarlyhe will see green flashes with dark intervals in the area C-C.

A wide variety of combinations are thus available with suitable timingmechanisms for various purposes.

Referring to Figs. 11 and 12, a three light beam projecting unit isshown wherein a housing I0 is mounted on a fixed base I I and encloses arotatable standard having three pairs of arms I2 arranged to rotateabout a common axis and each mounting a lamp I4. Each lamp M has areflector l 5 shaped and positioned to project parallel light beams outof the housing, the beam from one lamp passing through a red filter IS,the beam from the second lamp passing through a green filter ll and thethird lamp through a white filter Hi. In this arrangement three lampsare simultaneously in operative position and in a closed circuit, whilethe other three lamps are inoperative and in an open circuit and providean emergency set should any lamp of the other set burn out. In thatevent, the standard is rotated to replace the former operative set bythe second set of lamps and the replacement time thus kept to a minimum.The lamps can be timed by any suitable timing mechanism such as acommutator system 20 driven by a small motor 2 Having thus described myinvention, I claim:

1. A signalling system comprising means for projecting a red beam,having a light distribution pattern symmetrical about an axis, along acourse with the axis of the red beam angularly divergent from the lineof the course so that the said red beam is asymmetrical thereof, meansfor projecting a green beam, having a light distribution patternsymmetrical about an axis, along the same course with the axis of thegreen beam angularly divergent from the said line of the course andasymmetrical thereof, said red and said green beams mutually overlappingin a path symmetrical of the line of the course, said respective beamsforming a line substantially coincident with the line of the coursepartaking equally of the energy of both said beams so that the visualaspect of the formed line is a resultant of an even additive mixture ofthe two beam colors while the visual aspect even slightly to one side ofthe formed line is of an additive mixture of unequal energies in whichthe greater energy dominates and establishes the visual aspect.

2. A signalling range system comprising means for flashingsimultaneously a pair of complementally colored slightly divergent andoverlapping light beams of the same effective intensity and each havinga light distribution pattern symmetrical about an axis, and means forflashing a substantially white beam narrower than the combined width ofthe overlapping colored beams and superposed over the common axisdefined symmetrically of the overlapping area of the said twosimultaneously flashed beams.

3. The method of forming a unidirectional guide beam to identify alinear course from a position toward an objective, which comprisesprojecting a beam of light having a light distribution patternsubstantially symmetrical of an axis of peak intensity and ofpredetermined chromatic characteristics to continuously overlap saidcourse for substantially the full effective range of the beam and by apredetermined angle while maintaining said axis of peak intensitythereof at an angle to and on one side of such course, and projecting asecond beam of light having a light distribution pattern substantiallysymmetrical of an axis of peak intensity and of different predeterminedchromatic characteristics from the first beam to continuously overlapsaid course and the overlapping portion of the first beam forsubstantially the full effective range of said second beam and bypredetermined angles while maintaining the axis of peak intensity ofsaid second beam at an angle to and on the other side of such coursefrom the first beam to form a single composite beam, whereby theoverlapping portions of the first mentioned two beams between therespective axes thereof form a third beam having an axis coincident withsuch course and visually contrasting chromatically with both of saidfirst mentioned beams, said last mentioned beam at its axis being formedof equal energies of the first two beams and its intensity comprising afunction of the relative angularity of the overlapping portions of thefirst two mentioned beams.

4. In signalling, means forming a beam of light of predeterminedchromatic characteristics and having an axis of peak intensity, saidbeam form ing a light distribution pattern symmetrical about said axis,means forming a second beam of light of predetermined chromaticcharacteristics different from those of said first beam and having anaxis of peak intensity, said second beam forming a light distributionpattern symmetrical about its said axis means for simultaneouslyprojecting both of said beams together to form a composite observableguiding beam comprised of components of both of said beams, saidcomposite guiding beam containing the axes of both of said beams with anangular divergence between them forming spaced peaks of intensity witheach peak dominated by the chromatic characteristics of the beam havingthe particular axis, and said composite beam having an axissymmetrically between the first two mentioned peaks composed of anadditive mixture of the chromatic characteristics of both beams andbeing visually in contrast with both said first mentioned beams, saidthree beams when seen by an observer passing transversely thereof assuccessively a beam dominated by the chromatic distribution of the firstbeam, a composite beam partaking of the additive efiects of both beamsin a line symmetrically between the axes of the first and second beams,and a beam dominated by the chromatic characteristics of the said secondbeam.

5. A signalling range system comprising means for flashingsimultaneously a pair of complementally colored slightly divergent andoverlapping light beams of the same effective intensity and each havinga light distribution pattern symmetrical about an axis, with therespective axes in acute angular divergence to form a third beam havinga light distribution pattern symmetrically between said two axes, andmeans for flashing in alternation thereto a substantially white beamnarrower than the combined width of the overlapping colored beams andsuperposed over the common axis defined symmetrically of the overlappedarea of the said two simultaneously flashed beams.

EDGAR W. PENTON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,266,554 Coleman et a1 May 21,1918 1,348,855 Fessenden Aug. 10, 1920 1,442,681 Craig Jan. 16, 19231,989,295 Sewell Jan. 29, 1935 2,023,708 Spring Dec. 10, 1935 2,176,469Moueix Oct. 17, 1939 2,365,038 Adler Dec. 12, 1944 2,386,268 Roper Oct.9, 1945

